The invention relates to a device for sterilizing water flowing through a sanitary appliance, having
a) a housing, which comprises an inlet and an outlet for the water;
b) a UV lamp, which is disposed inside the housing and the radiation of which is directed towards the water flowing through; and
c) a throughflow chamber for the water, which is disposed in the housing and surrounds the UV lamp.
In recent years the dangers arising in the field of sanitation from water contaminated with micro-organisms, in particular bacteria, amoebae or other monocellular organisms, have become ever clearer. For said reason, increased importance is being attached to water sterilization. In said connection, there have been reports of experiments to sterilize flowing water through exposure to UV light, which is of a wavelength suitable for killing micro-organisms carried along in the water.
Such devices therefore irradiate, and hence sterilize, the water flowing through the throughflow chamber. The efficiency of such a device is influenced not only by the operating parameters of the lamp but also by whether the water actually flows through the entire throughflow chamber. Any dead spaces, in which air or other gases collect, inside the throughflow chamber lead to non-optimum efficiency of the UV lamp because this means that not all of the throughflow chamber accessible to irradiation is available for sterilizing purposes. If, allowing for such dead spaces, an adequate sterilizing effect is nevertheless to be achieved, a corresponding increase in the lamp wattage is therefore necessary. This is, on the one hand, expensive and may, on the other hand, lead to undesirable side effects such as an increase in the temperature of the removed water and/or of the sanitary appliance.
The object of the present invention is therefore to develop a device of the type described initially in such a way that the sterilizing efficiency of the UV lamp is increased.
Said object is achieved according to the invention in that a venting device is provided which removes the air or gas, which collects in the throughflow chamber, through the outlet.
Such a venting device eliminates the previously described dead spaces and therefore increases the sterilizing efficiency of the UV lamp and hence of the entire device. By virtue of the fact that removal of the air or gas, which undesirably collects in the dead spaces, is effected through the outlet, it is not necessary to provide special vent bores in the housing of the sanitary appliance, which would additionally entail measures to prevent water escaping from the sanitary appliance.
In an advantageous refinement of the invention, the venting device comprises a constriction of the flow area in the region of the downstream end of the throughflow chamber. Such a constriction leads to an increase of the flow rate of the water flowing, during removal, through the region of the constriction. Air or gas bubbles situated in the upstream catchment area of said increased flow rate are, as it were, sucked out of the throughflow chamber and so troublesome dead spaces are eliminated.
The constriction of the flow area is advantageously formed by a discharge bore in a partition between the throughflow chamber and an outlet chamber. In said manner, the constriction may be easily and inexpensively realized. The previously described suction characteristic of said constriction may be adapted by means of the pipe diameter to the prevailing conditions.
In a further advantageous refinement of the invention, the throughflow chamber is so designed that its highest region is situated at the downstream end of the throughflow chamber. The result of such a design is that air or gas bubbles forming in the throughflow chamber are conveyed, on the one hand, by virtue of the flow action and, on the other hand, by virtue of their buoyancy towards the downstream end of the throughflow chamber, where they may then be removed through the outlet.
The longitudinal axis of the throughflow chamber is in said case advantageously inclined relative to the horizontal. Thus, the previously described design of the throughflow chamber may be achieved without incurring additional outlay for manufacturing its shape.